why does time slow/speed down/up in some places, but not others? For example, pretend you're falling down a black hole within sight (telescopic) of the earth, and a second (to you) goes by. back on earth, the people looking at you through the telescope watch you move very slightly, over time, other scientists observe you, and they notice that you are glancing at your watch very slowly. same thing for when you travel at the sepeed of light, you go to another galaxy and come back, when you get back to planet earth, everyone that you knew is either old or dead. why does it happen?

"Civilization is a race between education and catastrophe."-H.G. Wells

Time dilation. As your speed gets close to the speed of light, time slows down for you and your apparant mass increases. If you were supposedly travelling at the speed of light, your mass would be infinite, which is why only massless objects such as photons can travel at that speed.

Keiji wrote:Time dilation. As your speed gets close to the speed of light, time slows down for you and your apparant mass increases. If you were supposedly travelling at the speed of light, your mass would be infinite, which is why only massless objects such as photons can travel at that speed.

but why does your mass become bigger and time slow down when you approach the speed of light? and what is time dilation?

"Civilization is a race between education and catastrophe."-H.G. Wells

There is no such thing as time. Time is determined based on our own frequencies and perception. We see 24 images per second. How fast you are traveling isn't going to change that.

If you were to see more than 24 images per second, then time would start to slow down in appearence for you, and everyone else would not feel it. This happens in accidents and such and is proven that you can see more stuff when your brain operates at more than 24 images per second.

Furthermore, speed is relative. According to the above theories, 1 side of the earth should happen faster than the other etc. As the sun spins around the galaxy, and the earth spins around the sun, and as the earth rotates on it's axis, then when you are on part of the earths spin that is in sync with the other movements(as a sphere, 1 part of it will always be there), and then on the opposite side of the earth you would be traveling slower on the universal position.

So, the entire thought of using speed to go faster than the speed of light to time travel is really nothing more than changing externally the amount of images per second to give the perception of time travel.

Just think about it like a movie. I'll use the matrix as an example, since they did alot of time slowing in the movie. For the majority of the movie, it sends you the same amount of images per second that is in sync with our own perspective. So what is physically happening when the show slow motion parts? They are sending more images per second to you than would be normal during the movements(of the movie's perspective), and thus gives the appearance of slower time.

So IMO, going faster than the speed of light is not going to time travel at all. You're brain will still be processing at the same frequency and the same images per second, only if you are going that fast it's only a distortion, not actual time travel.